1971 War: Sinking of the KHUKRI

"The Story of the Pakistan Navy" has recounted the events as seen from the submarine HANGAR which sank the KHUKRI.

HANGAR had sailed from Karachi on 22 November for a patrol off the Saurashtra coast. On 1 December, she was ordered to shift to the area off Bombay to relieve her sister submarine MANGRO who was completing her patrol.

On 2 December, HANGAR sighted the Western Fleet which was on its way to its patrol area. HANGAR reported this to Karachi and continued her patrol off Bombay. She was unable to find good warship targets. Thereafter "The Story of the Pakistan Navy" states:

"In an effort to locate the evasive enemy, HANGAR extended her patrol northwards to investigate some radio transmissions that she had intercepted on her sensors. In the early hours of the morning of 9 December, when she was off the Kathiawar coast, two contacts were picked up on her passive sonar on a north*easterly bearing. They were easily identified as warships by their sonar transmissions; radar indicated a range of 6 to 8 miles. A pursuit of the enemy began.

"When the first attempt to intercept the ships failed, the submarine began snorkelling to gain speed. HANGAR however, failed to attract the attention of the ships and contact was lost as the range increased. By the evening of 9 December, she was able to make out the pattern of their movement by tracking them with the aid of her sensors. The ships were carrying out a rectangular anti-submarine search.

"Forecasting their movement along this search pattern, the submarine succeeded by 1900 in taking up a tactically advantageous position on the path of the patrolling frigates. The range of the ships, which were moving at a speed of 12 knots, began to close. The crucial moment which the submarine had patiently worked for since the early hours of the morning had arrived. HANGAR was finally in a position to launch an attack.

"At 1915 she went to action stations. Fifteen minutes later she came up to periscope depth but could see nothing in the dark night when the range of the ships indicated by her periscope radar was only 9800 meters. The ships were completely darkened. The Commanding Officer decided to go down to 55 metres depth and make a sonar approach for the final phase of the attack. Unaware of the submarine's presence the frigates continued on their track. At 1957 HANGAR fired a down-the-throat shot with a homing torpedo at the northerly ship from a depth of 40 metres. The torpedo was tracked but no explosion was heard. This was not the time to brood over the situation. The control team sprang into action and fired a second torpedo. After five tense minutes a tremendous explosion was heard at 2019 hours. The torpedo had found its mark. The other enemy frigate came straight for the submarine. HANGAR fired a third torpedo and turned away at maximum speed. A distant explosion was heard subsequently.

"Moving west towards deeper waters where she would be less vulnerable the submarine passed very close to the scene of action and heard distinctly the noise of explosions emanating from the burning wreck. Later she came up to periscope depth and took a last look. In the dark nothing could be seen except a faint glow on the horizon near the scene of action.

"In an extremely vulnerable position in enemy controlled shallow waters where no help could reach her the task that lay ahead of HANGAR was to evade her pursuers in the hunt that followed-the first signs of which came when a number of underwater explosions were heard just about half an hour after the attack. For the next four days. HANGAR braved the might of the Western Fleet. All their anti-submarine assets frigates Seaking helicopters and Alize aircraft were thrown into the chase that followed. A hunter killer (anti-submarine) operation fully supported by IAF reconnaissance aircraft based ashore in the area was put into effect.

"The first priority of HANGAR after the attack was to get into deeper waters and put as much distance between her and the position from which the torpedoes were fired the datum (reference point) for the search by enemy units. Having successfully done that she began her journey back home. For four days and nights she was harassed by the enemy. The dimensions of the enemy anti-submarine effort can be gauged from the fact that about 150 underwater projectiles were fired in this period. Only on one occasion were the explosions close enough to shake the submarine.

"The Commanding Officer was naturally keen to pass the information of this successful attack to Naval Headquarters. The submarine had to come up as it cannot transmit radio messages while submerged. She took the risk of being fixed by enemy direction finding stations ashore while transmitting the message. Enemy aircraft were overhead soon after the message was sent. Intense air activity throughout the day forced the submarine to run silent and run deep reducing her speed of advance to 1.5 knots.

"There were of course many close calls during the passage back to Karachi. The Indian Navy called off the futile hunt on the evening of 13 December. There were claims by some of their units to have sunk the submarine but she arrived unharmed at Karachi on 18 December.

"In this spectacular action which took place about 30 miles south of Diu off the Indian Kathiawar coast. KHUKRI the ship of the Squadron Commander of the 14th Frigate Squadron was sunk within two minutes after receiving a hit in the magazine where explosives were stowed. 18 officers and 176 sailors including the Commanding Officer who deliberately stayed back on the sinking ship lost their lives. This came as a shattering blow to the Indian Navy deflating in one stroke the exuberance generated by highly exaggerated success stories of the missile attacks at ships off Karachi.

The Pakistan Naval Historical Review of March 1979 contained an article by a French naval officer. Cdr Courau. It states:

"At the beginning on the afternoon of the 8th there had been only two radar echoes detected twice in the same formation at an interval of one hour; this was enough to class them as warships on a south-easterly course. The hunt began.

"Since the sighting the enemy had continued to change course which gave the hunter some problems. On the evening of the 8th the enemy was on a north-westerly course then on the morning of the 9th they changed to a north*easterly course then to a south-easterly course about noon.

"HANGAR now realised that the enemy ships had been on a course that described a rectangle. Then at 1900 the ships set a course to the North West. At 1915 the CO estimated their mean course and dived to attack. He altered course on the frigate on the western side (KIRPAN) at very slow speed in order to present the smallest silhouette to the enemy's sonar. He decided not to hurry the moment of firing, but to wait for the moment the enemy would be on target judged to be at 2000.

"At 2013, a sharp order broke the silence *"Fire". Everyone was tense. The torpedo left the tube and was heard moving towards the target, but then they heard it passing under without exploding.

"There was no time to criticise this failure. The frigate on the eastern side (KHUKRI) passed in her turn at a range of about 5000 meres. There was just time to set the range and at 2017 a second torpedo was fired. A loud explosion was heard.

"KIRPAN returned to pick up survivors and her course brought her in line with the submarine which promptly fired a third torpedo but the frigate was prepared for the attack and left at high speed. After 8 or 10 minutes a very clear explosion was heard followed by the stopping of the KIRPAN's machinery. HANGOR considered that he had hit the frigate, but he decided to abandon the attack and made for deep water. KIRPAN had a badly damaged stern and was unable to steam, she was finally towed into Bombay.

"There followed three days of depth charge attacks by Shackeltons, Alizes and escorts. The submarine suffered 156 depth charges, most of which were a long way off. Every time the submarine used the schnorkel, it was spotted by aircraft, but the escorts led to the position by the aircraft never made contact. Finally the HANGOR managed to escape and carry on her mission."

In 1997, the Public Relations Directorate of Pakistan Naval Headquarters published "Sentinels of the Sea - The Pakistan Navy 1947-1997". It contains an article by Rear Admiral RA Qadri, who was the Electrical Officer of HANGOR. The following excerpts describe the attack on KHUKRI as seen from HANGOR.

"After having obtained a perfect (fire control) solution, HANGOR commenced the attack at 1957 by firing one homing torpedo, "down the throat" at the more northerly target, which was INS KIRPAN. The torpedo ran true and it was tracked on sonar all the way as it acquired "lock on" to the target and passed under it (as it was supposed to do). However, the newly acquired torpedoes, whose test facilities had not yet been set up, failed to explode and kept going. Until the time that the torpedo was fired, neither of the two frigates had any inkling of being under attack. However, the moment the torpedo passed under INS KIRPAN, she suddenly woke up, realised she was under attack and turned away at maximum speed. HANGOR had struck first, but had failed to hit hard. The new torpedo had let it down.

"The advantage had now shifted completely in favour of the enemy. If the enemy had kept their cool, it is difficult to say what would have been the final outcome. Perhaps, this article would not have been written in such detail. But one thing is sure - the fate of INS KHUKRI would still have been what it was.

"As KIRPAN turned away and ran, KHUKRI, which was to its south, now knowing the direction from which the torpedo had come, increased speed and came straight for an attack on HANGOR.

"It was now HANGOR's turn to keep it's cool and this, the submarine did well. As KHUKRI came in for the attack, HANGOR's attack team calmly shifted target to KHUKRI, obtained a quick solution and fired the second torpedo at it. This quick shot was mostly meant to spoil the attack by KHUKRI. However loss of nerve by KHUKRI's Commanding Officer on hearing the oncoming torpedo, made him try to turn away from it. This greatly helped to "pull" the torpedo towards the frigate. As soon as the torpedo acquired "lock on", it went straight for the target, passed under it and when it was directly under the keel it exploded, breaking the keel of INS KHUKRI which sank in a matter of two minutes, with all hands on board. There were no survivors. There was simply no time for the myth of the "CO nonchalantly lighting a cigarette as the ship sank under him" to be enacted.

"The sinking of KHUKRI had now made the balance of advantage even between HANGOR and KIRPAN and the action had not yet finished.

"Seeing its sister ship sink in such a short time must have been a nerve-shattering experience for the KIRPAN's Commanding Officer, for he came charging in for an emergency attack, fired off a pattern of depth charges, hoping to scare HANGOR into breaking off its attack. But when he found that HANGOR was not intimidated and instead had fired the third torpedo at KIRPAN, he broke off the attack just as quickly and ran "hell for leather" in panic trying to outrun the torpedo locked on to the frigate's tail. That was the last seen (actually heard) of her.

"What followed this action was a massive anti-submarine effort by the Indian Navy, in the form of Operation Falcon to hunt down and kill just one submarine, PNSIM HANGOR. The operation continued for four days till the night of 13 December.

"A number of anti submarine charges were fired, on what the HUK groups thought was HANGOR. In the submarine itself, 24 salvoes (each of three charges) on 10 December and 12 salvoes on 12 December were registered. The latter depth charging took place after the Indian Navy's shore stations had taken cross bearings on HANG OR's radio message to Naval Headquarters regarding the action.

"Throughout these four days, HANGOR remained completely aware of the huge effort underway (though the details of Operation Falcon as such were known only after the war). It is a measure of HANGOR's efficiency that in spite of leaving the action area with a highly depleted battery, and with such a massive hunt for her in progress, she managed not only to recharge her batteries but was able to successfully lay a false trail for the HUK groups to follow. How successful the false trail was, can be judged from the fact that of the more than 36 salvoes fired, none came anywhere near the submarine; only two slightly shook the submarine. Most, being far away, could just be heard on sonar."

Admiral Kohli's book states:

"While in the process of hunting, the enemy submarine with her superior sonar facility, obtained contact of KHUKRI before her own detection by the ship and struck KHUKRI by a salvo of three torpedoes in quick succession. The ship sank in a matter of minutes at 2055 on 9 December, taking down with her 18 officers and 176 men including the Commanding Officer, Captain MN Mulla. It was a serious blow in an encounter in which the superior underwater destruction capability and its allied weapons systems of a modern submarine turned the scales and thus the hunter became the victim. A subsequent technical enquiry also revealed certain failings and non compliance on the part of KHUKRI's A/S Team with the laid down A/S doctrine.â€

KIRPAN, who was searching for the submarine together with KHUKRI, reported detecting torpedoes going past her at the time KHUKRI was torpedoed. She took vigorous evasive action and fired mortars on the torpedo bearing. After a few salvos, her mortars went non operational. KIRPAN now faced a dilemma *should she rescue KHUKRI's survivors - either by going amidst them on a dark night or should she lower her boats to rescue survivors. Both actions would require KIRPAN to stop and this would make her an easy target for the submarine, if it chose to attack KIRPAN. Or should KIRPAN leave the area, repair her mortars and return to the area with an additional ship to rescue the survivors and start hunting the submarine? This however would give the submarine time to get away from the scene of the sinking and consequently greatly enlarge the area to be searched. The CO of KIRPAN decided to withdraw from the scene and return later.

Admiral Kohli's book states:

"There was some controversy about KIRPAN withdrawing from the scene of the sinking instead of picking up survivors. She had heard the hydrophonic effect of more torpedoes and she had defective mortars. In the circumstances she took the wisest course. After meeting with KATCHALL, she returned to the scene in her company to carry on with the hunt."

On receiving KIRPAN's signals reporting the sinking of KHUKRI, FOCINCWEST rushed rescue forces to the scene. By the time KATCHALL and KIRPAN returned the next morning, only 6 officers and 61 sailors had survived to be rescued.

FOCINCWEST cancelled the third missile attack on Karachi which was to be have been carried out on the 10th night and deployed forces to hunt the submarine.